1. Field of the Invention
The present invention relates to a high quality color filter without a void, or the like, to be used for a liquid crystal display apparatus.
2. Description of the Related Art
Recently, with the development of the personal computers, in particular, the development of the portable personal computers, demand for a liquid crystal display, especially a color liquid crystal display tends to be increased. However, the color liquid displays are expensive; therefore, a request that the cost should be reduced has been increasing. In particular, a request that the cost of their color filters, which accounts for a high ratio in the total cost, should be reduced has been raised.
Such a color filter, in general, comprises colored patterns of three primary colors of red (R), green (G) and blue (B) so that liquid crystals are operated as a shutter by switching on or off the electrodes each corresponding to the pixels of R, G and B. Thereby, color display can be provided according to light transmission to the each pixel of R, G and B.
As the production methods for a color filter executed conventionally, for example, a dye method, a pigment dispersion method, or the like can be presented. However, according the methods, in any case, the same step should be repeated for three times for coloring the three colors of R, G and B so that problems are involved in that the cost is increased or the yield is lowered due to the repetition of the steps.
Then, a method of forming a semiconductor photo catalyst containing layer on a base material, using a semiconductor photo catalyst containing layer forming coating solution containing a semiconductor photo catalyst and a material to have the characteristic change by the function of the semiconductor photo catalyst according to the energy irradiation, and exposing in a pattern so as to form a pattern with the characteristic change, or the like has been discussed by the present inventors (Japanese Patent Application Laid-Open (JP-A) No. 2001-074928). According to this method, a colored layer can be formed easily, utilizing the characteristic difference of the above-mentioned semiconductor photo catalyst containing layer.
Moreover, as an application of the method, also a method of directing an energy to a patterning substrate comprising a transparent base material, a light shielding part formed on the base material, and a semiconductor photo catalyst containing layer formed so as to cover the light shielding part from the base material side for changing the characteristic of the semiconductor photo catalyst containing layer only in the region without the formation of the light shielding part is discussed by the present inventors (JP-A No. 2004-212900). According to the method, it is advantageous in that the pattern with the characteristic changed can be formed without using a photo mask, or the like, and a method of, for example, utilizing the same at the time of forming a striped colored layer used for a striped color filter or a zigzag colored layer used for an IPS mode color filter is also discussed.
Here, according to a color filter having a striped colored layer or a colored layer of an IPS type color filter, since a light shielding part 4 is formed so as to be crossed with each colored layer 8 for example as shown in FIG. 7A, in general, the colored layers are formed by coating a colored layer forming coating solution not only of the pattern for forming the colored layers, that is, the opening parts sectioned for the light shielding parts for forming the colored layer but also on the light shielding parts crossing with the pattern so as to form the colored layers. However, in the case the above-mentioned method of exposing the semiconductor photo catalyst containing layer from the base material side is used, the characteristic of the semiconductor photo catalyst containing layer only in the opening parts sectioned by the light shielding parts is changed without changing the characteristic of the semiconductor photo catalyst containing layer on the light shielding parts crossing with each pattern. Therefore, in the case the colored layer forming coating solution is coated, the colored layer forming coating solution cannot be adhered onto the semiconductor photo catalyst containing layer on the light shielding part crossing with the above-mentioned colored layer so that the colored layer forming coating solution 10 cannot be spread neatly to the end parts of the opening parts sectioned by the light shielding parts 4 as shown in for example FIG. 7B so that irregularity or a void can be generated in the colored layer.
Moreover, as another example of a production method for a color filter, a method of forming a bank for storing a colored layer forming coating solution for forming a colored layer on a base material, applying a plasma process to the bank with a fluorine composition as the introducing gas so as to have the bank as liquid repellent, and forming a colored layer by the ink jet method is also proposed (JP-A No. 2000-187111). Also in this case, the colored layer forming coating solution cannot be adhered on the liquid repellent bank to be crossed with the striped colored layer, or the like so that as in the above-mentioned case, the colored layer forming coating solution cannot be spread neatly to the end parts of the opening parts sectioned by the light shielding parts, thereby irregularity or a void can be generated in the colored layer.